Virtual Worlds (VWs) like Second Life provide a multiuser 3-D environment that may be utilized for either classroom-based or autonomous language learning. While Second Life is one of the most popular VWs at the current time (especially if differentiated from Massively-Multiplayer Online Games like World of Warcraft), there are a number of other VW platforms that, taken together, dwarf Second Life in terms of users. A few of these include: Active Worlds, Entropia Universe, Furcadia, Club Penguin; and MMOGs like the aforementioned World of Warcraft, Runescape, Lineage II, etc. In addition to these worlds, there are also more customized environments such as Croquet and OpenSimulator. As researchers and teachers of languages, our challenge is to determine which of these environments, if any, is appropriate for the group(s) of students we wish to teach and/or study. This article will provide a rationale for the use of VWs in education and also an overview of some of the most applicable Virtual Worlds and discuss the strengths, weakness, and dangers of each.